condition mean min max ZT0-3 21.7547 21.7547 21.7547 ZT4-7 20.9309 20.9309 20.9309 ZT8-11 20.574350000000003 20.574350000000003 20.574350000000003 ZT12-15 22.852400000000003 22.852400000000003 22.852400000000003 ZT16-19 28.52225 28.52225 28.52225 ZT20-23 23.903100000000002 23.903100000000002 23.903100000000002